Onboard Water Tank w/Elec. Pump Questions

[StumpXJ]

Ok, so I have my suspension mostly done on my trailer, and I decided today would be the "install water tank, pump, and plumbing day" since the trailer is standing up on its end and I can work on the bottom easily. I got it all installed, but I am curious on the plumbing aspect. I dont have any pics, but will describe what I am working with.

I have a 16 gallon RV plastic (polysomething or other) tank that's ok for drinking water, kinda square/rectangular like a box. Its mounted under the trailer roughly near the axle.

It has 4 outlets. one large for the fill, and three smaller. I know one will be the vent, and the other will be the feed to the pump, and I assume the last one is a return of sorts?

I have just a simple 12volt pump that I will use with a toggle switch to turn on for pressure. I ran the feed line from the tank into the pump, and then from the pump, I was thinking I should go to a T fitting with the 'inline' portion of the T then going out to my spray head. The smaller branch off of the T will go to the return nipple on the tank so that it circulates the water while the pump is on, and the spray head is not being used. I assumed this will be better than just deadheading the pump?

Am I off in my thinking? I dont intend to ever run the pump for long without using the sprayer head, but for those few seconds to a minute (say between washing dishes), I dont want to have to turn the pump on and off.

Somebody steer me right here, or tell me how to do it correctly.

Ideally, I want to turn on the pump, and use the sprayer whenever I want as intermittently as I want, without hurting the pump by deadheading it. I was assuming also that when the spray head is in use, the water will come out of it as apposed to continuing to circulate since its the path of least resistance, and the recirculating portion of the T is much smaller in diameter compared to the sprayer head portion.

I am probably making it harder than it should be, but just want to run it by you guys. I am finishing up the plumbing tomorrow.

~James

 

[dustboy]

What you're thinking might work, but you'll need a valve to restrict the return line. If it's wide open you won't get much pressure to the spray head.

Which pump do you have? The one I got has a pressure switch built in, so I just leave it switched on and it pumps when I open the valve.

 

[StumpXJ]

Im not even sure where I got the pump from, its a simple one, and it doesnt have a pressure switch. That would be ideal, what pump do you have?

I thought about installing a valve, but then that gets to aggravating. Maybe I will try it with just the T and see how it works. It'll be easy enough to change I suppose.

No one else have anything? Does everyone have a pressure switch controlled pump??

EDIT:

So I just checked out the Shurflo pumps, and they have the switch integrated. They also draw half the amperage of the one I have. The Shurflo would make my life a lot easier.... looks like I will be getting one. I guess I will just cap off the extra outlet on the tank.

Thanks!

 

[R_Lefebvre]

The extra small hole on the tank is for a drain. You should put a petcock on it. I have a pump without a pressure switch and will simply use a pushbutton to power it as needed.

 

[StumpXJ]

Good point on the drain... didnt think of that. I have a petcock that will fit right in there too.

I just think the Shurflo with the built in switch will be easier, especially for those other than me using the system (wife, etc.). Not sure, the Shurflo is $60 bucks, and I already have this other pump... May just try it as is since I have most of it installed already.

~James

 

[overlander]

Good point on the drain... didnt think of that. I have a petcock that will fit right in there too.

I just think the Shurflo with the built in switch will be easier, especially for those other than me using the system (wife, etc.). Not sure, the Shurflo is $60 bucks, and I already have this other pump... May just try it as is since I have most of it installed already.

~James

Sell it on ebay and get the shurflo. I wouldn't even think of trying to do what you are doing without a pressure switch pump. The difference in convenience of use is going to be huge, and the non-regulated pump will have to run the whole time, not intermittent.

 

[kellymoe]

I bought a 20 gal water tank last summer and have been thinking of ways to mount and deliver the water. I have a electric pump but I have also been thinking of a hand pump for reliability. My father makes billet aluminum hand fuel pumps for vintage race cars. I think I am going to mount one of his pumps remote from the tank. I like the idea of not relying on battery power. Just a few pumps are sufficient to pressurize the tank enough to give you a good flow for a minute or two of use. I will also keep the electric pump mounted to it's current location to use as a back up or maybe for taking a shower, although I dont really see myself using this tank for shower use.

The hand pumps my dad makes are great little units and very versatile. Being that my truck is carburated I can also use the same pump as a back up fuel pump if my electric fuel pump fails.

 

[dustboy]

I just think the Shurflo with the built in switch will be easier, especially for those other than me using the system (wife, etc.). Not sure, the Shurflo is $60 bucks, and I already have this other pump... May just try it as is since I have most of it installed already.

~James

That's the pump I have, it's great. Makes plenty of pressure, and you can get rebuild parts for them. I even froze mine and once it thawed it worked fine.

 

[REasley]

Be sure to put a filter between the tank and the pump. Besides all of the potential stuff thats in the water or filler hose, there are usually small shards of polyethylene in the tank from drilling the holes for the bungs (even the tanks with spun-weld fittings). Those shards will get caught in the pump valves. Then the pump will run, but not pump.

You could use the continous run pump without deadheading it. Just put a springloaded pressure relief valve on the return line. When you shut the sprayer head off, the valve will open and bypass the flow.

Kellymoe
Is the 20 gallon tank poly? If so you may run into problems trying to presssurize the tank. The tanks tend to flex and distort under pressure. Unless the fittings are spun-welded into the tank, you may have to deal with leaks.

 

[jim65wagon]

The Shur-flo pump works great. No return line needed for it and it has instant pressure. In the Tundra I have the tank connected to the pump with quick connect fittings. When we're done travelling, I just open the sprayer nozzle and run the pump until the tank is nearly empty. Unplug the quick connects, pull the tank onto the driveway with the fill opening at the bottom and the tank drains and dries quickly.

 

[Philberto]

I use aquatainers rather than RV tanks, but I can tell you that of course the large hole is for filling, one small hole is for feed for the pump, one for vent, and I would use the other hole (return line) to fill the tank if you must do so from an unpressurized source (think siphoning and filtering water from a lake/stream) Just put a bypass valve before and after the pump, and make sure there's a filter just before the pump intake. after the pump, one way goes to the shower head, one way goes back to the tank. Before the pump, one way comes from the tank, one way comes from a suction hose. I'm using a FloJet Triplex diaphragm pump with a pressure switch, and it's definitely the way to go.